public void ExtractByBinaryOperatorSubtract()
 {
     IValueExtractor ve = new BinaryOperatorValueExtractor(
         new NamedValueExtractor("field"),
         new NamedValueExtractor("otherfield"),
         BinaryOperatorValueExtractor.MathOperation.Subtraction);
     var obj = new ClassTest1();
     obj.field = 10;
     obj.otherfield = 34;
     Assert.AreEqual(-24, ve.ExtractValue(obj), "Binary Extractor does not work.");
 }
 public void ExtractByBinaryOperatorUnknownOperator()
 {
     IValueExtractor ve = new BinaryOperatorValueExtractor(
         new NamedValueExtractor("field"),
         new NamedValueExtractor("otherfield"),
         (BinaryOperatorValueExtractor.MathOperation) 10000);
     var obj = new ClassTest1();
     obj.field = 10;
     obj.otherfield = 34;
     ve.ExtractValue(obj);
 }